ECG Hypertrophy of Atria and Ventricles (Johnston) Flashcards
Atrial Enlargement occurs because of either an
- Increase in volume of blood in the chamber or
- Increase in resistance to blood flow out of chamber
- Volume overload or diastolic overload–dilation
- Pressure overload or systolic overload–causes hypertrophy
Leads to recognize for atrial enlargement;
R vs L atrial activation
- Leads I, II, III and V1
- RA activated first, LA activated later!!
Normal morphology of P wave
- represents atrial depolarization
- should be rounded contour (not pointed, tall peaked or notched, wide and M shaped)
- Should not exceed 3 mm
Increased amplitude of P wave indicates
-hypertrophy, HTN, AV valve disease, for pulmonale, congenital
RAE morphology on ECG
-p wave tall, pointed, taller in III than in I: P-pulmonale
LAE morphology on ECG
- p wave wide, notched; taller in I than in III
- P-mitrale
- 2nd half of P wave negative in V1 or III
RAE associated with
- Tricuspid Valve disease or pulmonary HTN
- COPD, PE, Mitral Stenosis or Mitral Regurg are causes of pulmonary HTN
RAE
- P-pulmonale peaked P wave with amplitude greater than 0.25 (2.5 mm) mv in leads II, III, AVF and greater than 0.1 mv in leads V1 and V2
- P wave has slight rightward axis
Right deviation seen in
- Lung disease
- Tall, thin, and tear shaped cardiac silhouette
- Especially seen in emphysema
LAE
- P-mitrale
- M signs to P wave, broad, notched P wave duration 0.11 sec and amplitude of terminal negatively directed portion in V1 to greater than 0.1 mV or 1 mm deep and 0.04 sec wide with slight axis of P wave
Causes of LAE
-Mitral stenosis or Mitral Regurg
inverted P waves before QRS complex in leads I, II and III think what?
- Low atrial junctional rhythm
- Also see upright p wave in AVR; but inversion of p waves in I, II and III
Most common cause of LVH is? Other causes
MCC: HTN
-Other causes: Aortic stenosis, Aortic insufficiency, Hypertrophic cardiomyopathy, and coarctation of aorta
Features of LVH
- Wall of LV is thicker so impulse will take longer to traverse it and arrive at epicardial surface
- Voltage and interval of QRS complex will increase, producing deeper S waves over RV and taller R waves over LV
ECG pattern of LVH fails to distinguish between
- concentric hypertrophy and dilated chamber so better to refer to as ventricular enlargement
- ECG can’t distinguish because it is total muscle mass of ventricle that mainly determines QRS voltage
Criteria for LVH–sensitivity and specificity
-sensitivity low–40-50% but are specific (high–90%)
Sokolow Lyon Criteria for LVH
- R in I + S in III > 25 mm
- R in AVL > 11mm
- R in V6 > 26 mm
- Called “Strain pattern”
RVH causes
-Chronic lund disease–COPD
-RVOT obstruction, VSD
Congenital–TOF, pulmonic stenosis, Transposition of great vessels
-Long standing Mitral stenosis, tricuspid regurgitation
RVH morphology
- R waves assume prominence in right precordial leads and deep S waves develop in left precordial leads
- R:S ratio greater than 1
Clues to RVH
-RAD + 90 OR MORE
-R in V1 is 7 mm or more
-R in V1 + S in V6 10 mm or more
R/S ratio in V1 >1 or more
-S/R ratio in V6 >1 or more
-Late intrinsic deflection in V1 0.03 or more
-Incomplete RBBB
-ST-T strain pattern in II, III, AVF
-P pulmonale
-S1 S2 S3 pattern (children)
Causes of dominant R waves in V1
- RVH
- Posterior or lateral MI
- WPW
- Hypertrophic cardiomyopathy
- Muscular dystrophy
- Normal variant
